Could refreezing the north and south poles reverse global warming?

By Mark Waghorn via SWNS

Global warming can be reversed by refreezing the poles, according to new research.

Blocking the sun would restore Earth's ice 'caps' at the north and south - maintaining weather systems.

The ambitious idea sounds like a crazy plot from a sci-fi blockbuster - but it is "both feasible and remarkably cheap," researchers claim.

Aircraft would fly over the Arctic and Antarctic spraying particles - known as a stratospheric aerosol injection (SAI).

They combat greenhouse gases by dimming starlight - cooling the whole planet, say the US team.

The first author Professor Wake Smith, of Yale University: "It would seek to abate climate change by deflecting back into space a small fraction of the incoming solar radiation."

The study found it would only have to be done in the sub-polar regions. Previous proposals have suggested using the technique across the planet.

It would quickly envelop the poles and may arrest or reverse ice and permafrost melt at high latitudes - stopping sea level rise.

Effective deployment at much lower altitudes than would be required in the tropics also presents fewer aeronautical challenges..

Prof Smith said: "Our model estimates the cost of implementing the subpolar SAI program to be $11 billion annually in 2022.

"This is less than a third of the estimated $36 billion to cool surface temperatures of the entire globe by 2°C."

Most savings are due to the vastly smaller area and fewer planes carrying five times the payload given substantially lower altitudes than covering the tropics, for instance.

Operating costs also included crew, insurance, maintenance and ground, navigational and landing fee charges.

Prof Smith said: "The Arctic faces a particularly dire threat from climate change, warming at roughly twice the global average."

The annual average surface temperature increased by over 3°C between 1971 and 2019. September sea ice extent in 2010-2019 was 40 percent lower than in 1979-1988.

Prof Smith said: "By mid-century, if not earlier, summer Arctic sea ice will likely have effectively disappeared, with potentially catastrophic climate consequences for the planet as a whole."

The Antarctic is also warming faster than the planetary average - with ice sheet melt a potential climate change "tipping point."

Smith said: "Stratospheric aerosol injection (SAI) is a prospective intervention that would seek to abate global warming by slightly increasing the reflectiveness of Earth's upper atmosphere."

It is not a replacement for other strategies including mitigation, adaptation and carbon dioxide removal, he pointed out.

Smith said: "The vast majority of simulations involve deploying aerosols globally in order to lower temperatures worldwide.

"This paper considers an alternative scenario whereby SAI might be deployed only in the sub-polar regions."

The IPCC (Intergovernmental Panel on Climate Change) has presented a "sobering picture", he said.

The average global surface temperature in 2011-2020 was 1.09°C higher than in 1850 to 1900. By 2018, the global average sea level had already risen eight inches since 1901.

Prof Smith said: "Under all shared socioeconomic pathways that serve as a basis for climate projections assessed by the IPCC, global surface temperatures continue to rise until at least mid-century.

"Perhaps most concerning, many changes caused by past and future greenhouse gas emissions are irreversible for centuries to millennia."

Record smashing heatwaves were reported earlier this year in both the Arctic and Antarctic.

Melting ice and collapsing glaciers at high latitudes would accelerate sea level rise around the planet.

Prof Smith said: "Fortunately, refreezing the poles by reducing incoming sunlight would be both feasible and remarkably cheap.

"We propose to inject only in the spring and early summer months, which is to say March to June in the Northern Hemisphere and September to December in the Southern.

"Since the intended effect of deployment is to deflect incoming sunlight, deployment in the local winter would have limited impact, as there is little sunlight in the region."

He added: "An SAI program with global benefits that would entail deployment directly overhead of far less than one percent of the world’s population and nearly none of its agriculture may prove an easier sell to a skeptical world than a full-on global deployment.

"Given its apparent feasibility and low cost, this scenario deserves further attention."

The study is published in the journal Environmental Research Communications.